It sounds like you host has either some very, very high restrictions or they don't know how to setup a host to allow the host to modify files created by PHP. Neither one of those things is a good thing when it comes to hosts.
There is nothing we can do about a host that has restrictions like this. The game is setup to run totally without the need to change permissions or ownership as long as the host is SET UP PROPERLY and we have no control over that.
If you use the installer program for installing all of the files then you do not need to change any permissions as they are set already.
I don't know what to tell you. The fact the host will not let you delete any files created by PHP tells me the person running the server needs a lesson in setting ownership and permissions for hosts because they are wrong for hosting.
If you are paying for the hosting or even if it is a free host I would move from them to a better hosting company because they should allow you to delete ANY file inside your host directory no matter who created it.
Your problems are probably created by how your hosting company has things setup on the server. And as I said there isn't anything we can do about it or anything we can do to help you.