Dispute with other flat owners what can be done

Hi, I own a flat in apartment of 8 flats. The apartment is not registered. I have been asking other flat owners to register the apartment since last 7 years. But they have always chosen to ignore it. They demand to pay maintenance charges only in cash. I want to pay the charges by cheque or online mode. But they refused my cheques of payment since the apartment does not have a bank account. Also the other flat owners use my parking space without my permission and restrict my usage of common spaces. The flat owners have also time and again abused me and my family, created nuisance at my place and made false accusations of misbehaviour against me. Due to non registration of apartment and failure to protect my interest as a flat owner I stopped paying maintenance charges in cash. Since then they have been threatening to cut my water supply. I am always ready to pay my maintenance charges but on condition that i get a valid receipt for the same.Please suggest me what can I do in this issu