office 365 AT&T Support

I know that if we purchase office 365 via a vendor, it doesn't normally come with free support.But AT&T approaches to us that they can provide support for Office 365 if we purchase licenses through them.  but i am not sure how reliable is the support? is anyone have experience with them?  we have another vendor that we used to work with who can offer a little cheaper than Microsoft Online price(AT&T only matches Microsoft's) and they have discounted hour rate(like block of hours) for ongoing support. What i mean support is like if we have an issue or we are not comfortable to run some power-shell commands, they can give us advise or help us remotely.