Maintenance to be paid from date of possession or date of sales?

Dear sir, I bought a 3BHK apartment on 31.10.2020 (as registered in sales deed). However, the builder delayed handing over the property till 03.03.2020 (as recorded in the possession letter). Now, the association of home owners are asking us to pay the maintenance from the date of sales instead of the date of possession with interest. I studied the sales deed to understand if there were any binding clauses regarding maintenance and found only the below listed. “The Purchaser/s has agreed that the Purchaser/s shall become the member of the Association that would be formed of all the Purchaser/s of the undivided share in the property and the Purchaser/s covenant to be subjected to the rights and obligation specified in such association and abide by all the Rules/Bye-Laws of such association. The Purchaser/s, when called upon by the Vendor, shall come forward to acquire the membership of the association and shall execute such documents as may be required”. The bye-law document shared by the association has no clarity on the start of the maintenance period. Under such cases, please advise which of the options would be the best course for me, 1. Pay the maintenance and then send legal notice to the builder to reimburse me 2. Refuse to pay the maintenance 3. Pay the maintenance Thanks, Arun