Reback payment problem from unite students

Hello, good day. This is the first time I have encountered such an incident within the borders of England and I wanted to tell you about it. My son, who was studying at Bournemouth University in England in his first year of university last year, stopped studying after completing his first year. After taking a break for a year, he received acceptance from De Mont Fort University, another university in England, and made preparations to start his second year. He applied at the visa application center on September 19, and the UK T4 student visa, which normally takes 2 weeks, did not arrive for 1.5 months. My son's university was starting on October 2nd, but since he couldn't make it in time, he said he could start the university in September, since his visa was not issued again, they said that the university could start in November, and if the visa was not issued again, he would not be able to go to university until January. My son's visa did not arrive in November, so he contacted DMU and said that he would not come to school and started the cancellation process. There is no problem so far, the visa application center said that the visa was delayed due to the density. My son rented a room through Unite Student, with which the university has an agreement, for both visa procedures and online registration to the university. This is an accommodation service that must be rented compulsorily and is rented for a minimum period of 40-45 weeks, with a monthly payment paid. My son could not start university due to reasons beyond his control, and during this period, 674 pounds of rent was deducted 3 times from the credit card whose dormitory information was entered. When my son sent an e-mail to cancel, they said that they had such a policy that they could not cancel or refund, but this policy had expired and therefore they could not make a refund. When I asked what the cancellation process was, they said that rent would be deducted from us until a replacement tenant was found, without refunding the money. My son paid for a service he did not receive for 3 months, and because the university, which he could not attend due to reasons beyond his control, constantly postponed the start date, he could not cancel or refund his accommodation beforehand, because even when entering the United Kingdom, you are asked where you will stay, it is mandatory to get accommodation service. However, Unite students insist on not making a refund despite these events even though we have proven the events with documents.