REPAIR OF TAB AND THEN A REPLACEMENT OF TAB

I took my tab into Smart lab in Tygervalley because the internet connection did not want to work. They made me pay for a new battery and only to find out that it was not the problem. I took it back 4 times and every time I got the tab back without it being fixed. Then as a last resort I did a sim swap and used it in the tab for 2 weeks still the internet connection would not work. Then I contacted Samsung directly. Asking them the way forward. After about another 3 weeks they replaced my tab with a new one. Got home and it did not even want to switch on. Phoned the call centre from smart lab the next morning. They said I must take it back and the must replace it with a new one. I took the tab back to smart lab. After numerous calls and emails from my side I did receive a new tab after another 3 weeks. I took the tab home and switched it on. But I cant use the tab for nothing. I cant bbm or whatsapp on the tab. I want to use the tab as a substituted for my phone. But now I am worse of that before. I contacted Samsung again and explaining this to them and asking what to do. I am still waiting for an answer after I send 3 mails asking for an answer. Its been 6 months now.