issues with xbox 360

I have an Xbox 360 S which has some problems (mostly regarding xbox live)

1. It has corrupted files located in the memory unit, however when I delete the corrupted files and close the Xbox, they reappear. This only happens to the memory unit. I tried moving the account to a different storage unit, and once I restarted the Xbox the account reappeared in the memory unit along with the one I moved.

2. Every once in a while I'd get a message saying something along the likes of "There is an update available from Xbox Live, you will be unable to connect to Xbox Live until the update has been downloaded." When I tried downloading the update, it would display an error code ending in 8015-000B.

3. If I try connecting to Xbox Live from the dashboard it says I cannot cannot to Xbox Live and that I should check my connection to Xbox Live, when I do so it fails at the part where it goes from Internet to Xbox Live. I tried with an Ethernet cable and nothing changed, except for when I try downloading the update mentioned in problem 2, it doesn't even start and gives the error code 8015-1802. An xbox support page said this was a connection problem, but I still have the other error code and the corrupted files.

Another concerning thing is that when I was trying to find information about any sort of solution, I found 2 pages saying the Z code in the connection error status report meant a suspension or ban code if it wasnt "Z: 0000-0000". After failing the xbox live connection test and I check the error status report, my Z code is 8015-000B. I have never connected to xbox live previously and also have never tampered with the console. I haven't found information about this certain code meaning a ban or suspension, but I was still spooked after seeing that.

Please help me, thanks in advance!

:)