No Response, Not their Problem

We have rented a property from Rawson Properties in Croydon. Deposits, monthly rent etc was always paid by us on time. Now that our lease has expired and we have moved out, we are told 2 weeks after that our deposits will only be paid back 14-30 days after moving out. This was not what we were told in the beginning. And when we email or call them, either NO RESPONSE or we are told to deal with the owners as it’s not their responsibility. Yet we were expected to make sure payments were made on time!!! TOTALLY UNACCEPTABLE AND IRRESPONSIBLE.