Phone being refused for repair

I bought a Samsung S30at exact thulamahashe last year black Friday using my exact account to use it during may/june exam because am a student . after a month it gave me a problem i sent it to be fixed. It took 2 months to be returned to me due to covid 19. A week after receiving the phone from repair it gave me problem again so on the 01 august 2020 i sent the phone back to the shop becouse it was not working. 2 days later i went to the shop to check if the phone was collected for repair and i was told it was still in tge shop. After a week i went to check and i was told the same story. I called the customer service and i was told the manager need to escalate the phone issue, there manager called while i was there and the consultant did not help me. Even today the phone is still in the shop not collected for repair and i don't have a phone to use for my assignment and to prepare for exam as it is due soon.. Iam the one going there to get feedback. They do not bother to call me and inform me but if i was owing them they were gonna call me day and night. Am unhappy with the shop and its head office they do not care about their customers they only care for money. Now i have to fail because of them. Am realy disappointed and hurt. I see people complaining about the phone department and they don't improve. Please assist me as Exact is not will to assist me