Unresolved issues to my phone

I am having a cellphone contract with cell c network provider. I've received the phone on the 5th of Nov 2018 OK fine. But here is the problem I can't download anything from this phone. I called them asking them to help me with the settings they told me it's technical problem so they gave me a number for tech department but it was not answered, instead it cut off. I went to the nearest branch and the guy that was helping me gave me a hell of an attitude telling me that why did I took the phone contract online when I knew that there's a cell c store in kokstad hence they gave me a cheap phone because it's for those who can't afford better phones and he didn't help me anyways. So was worried that how come they sell me a phone they know very well its not good and that I can't download anything. And I use the phone for almost everything but the only thing that is on this phone is whatsapp I don't even know how I did it to be there. I can't even view important documents from my emails because I have to download pdf and every time I try to do that it gives me the message that says "pdf can't be downloaded, try again later or if the problem continues get help troubleshooting..... So Im worried how can I pay for the phone that only has whatsapp and not other apps. Today (02-12-18) I called them again and after 30 minutes of staying on the line I get someone who gave me the settings but still there's no change. So how I am supposed to use this phone that has no apps like seriously. That's my concern and I will be paying full amount whereas I can't access the things I should be accessing. It's really confusing. I thought when you give someone something you give them so that they can appreciate it but now looks like I'm stuck with this phone I can't download the stuff I really need in a phone.