I am very disappointed in PEP

I bought a phone at Pep on March 15 and now it started overheating day before yesterday and yesterday, so Today I tool it back to change it as per their 7 day policy but they told me my 7days ended yesterday, how?? when it’s day 7 today

They didn’t help me ,I even called the manager n they made a phone call to someone higher none of them helped me. I am stuck with the phone I won’t w able to use and I don’t have a phone at the moment