Question about Property Laws

Dear Rabbis, shlita, a question about property laws: (I would appreciate a detailed answer, attached is a donation for the effort) We rented an apartment from an association 3 years ago and have now left it. In our memory - vague due to the long time that has passed, and not with certainty, - it was agreed that we do not need to pay for water. Although the contract explicitly stated that we would have to pay for water, we were told - certainly regarding other issues, and perhaps also in this context - that the association has many types of apartments, and there is a standard contract text, so not all things written in the contract are relevant to our rental, this is the official contract, but the actual reality would be different from what is written in the contract. Certainly - the broker told us that we do not need to pay for water. We found an email correspondence from the time of signing the contract in which we asked the responsible clerk about the broker's words to verify their correctness, but for some reason, he did not respond to this question, neither affirmatively nor negatively, but addressed other issues. For 3 years we were not required to pay for water. It should also be noted that there was no monitoring of the water meter by the landlord. After 3 years, when we came to leave the apartment, it turned out that about six months earlier, the association's clerk responsible for rentals - Reuven, was replaced by another clerk - Shimon. Shimon claimed that we need to pay for water retroactively. When we asked how we could pay if the water meter was not checked, he replied that he photographed it six months ago (when he took office) and according to this, we can roughly estimate how much we need to pay since we moved into the apartment. It should be noted that he did not talk to us about this from the time he took office until we left. We approached Reuven, and he said he does not remember what he agreed with us at the time, only that he can say he himself did not collect water bills from the previous tenant, and the policy was not to collect water from tenants, and he wondered - why not collect from the tenant before you as well. From his words, it became clear that he would certainly have let us leave without paying. We returned to Shimon and told him that although according to the dry contract he has the right to collect from us, nevertheless, it is not fair and not honest, when it is agreed by Reuven, with whom we signed the contract, that he would not have collected from us for water, and therefore it is likely he gave us to understand so. Shimon turned to the association's management, and they told him that they leave the decision in our hands, to do what we think is right from the perspective of fairness and according to a rabbinical question. Several clauses in the contract related to the matter are noted (I will only point out what I wrote above - that we were told the contract is in a standard form - although there are things that are not relevant to our rental): A. "In addition to the rent, the following payments shall be borne by the tenants, etc., the use of water, etc." B. "In any case where the landlord does not immediately use his rights arising from this contract, this shall not be considered a waiver of consent or acknowledgment on his part, and he may use these rights at any time he wishes." C. "The provisions of this agreement prevail over any agreement made previously, whether in writing or orally." Thank you very much.If more details are needed - please contact me.

Shalom and blessings

I apologize for the delay in the response, it took time to obtain the judges' answer on the matter:

It is difficult to exempt from paying for the water.

Since you yourselves are not clearly sure that it was agreed with you not to pay for the water. Additionally, it is written in the agreement that the provisions of this agreement prevail, so there is no way to exempt.