My bike is 7 months old and I ride it to work and back 5 days a week (16 miles a day) in the last two weeks the chain has started to slip when ever I go up a slight hill or start off in anything over 15th gear. I clean and lube the chain regularly and I noticed today the chain is not sitting on the chain ring properly. The gears change the same as the day I bought it.

Any thoughts?

Thanks

Elaborate on this point.

This kind of thing is something anyone with a little mechanical experience can diagnose very quickly by looking at it, but almost impossible to diagnose by a description like you've given.

you may just need to adjust the cable tension on your shifters.

You MIGHT have a worn chain.
Mileage is kinda low. But not impossibly so.
Post a pic, or do a net search for "how to measure chain wear".

5 days a week
7 months (about 30 weeks)
16 miles per day
=============
About 2400 miles

That is well within the range of a chain wearing out, especially if it has seen significant use in the rain.

Measure your chain length. Typically 12", if it is 12 1/16, between pins, then it is time for a new chain. If it is 12 1/8", then it is past time for a new chain.