Why there can't be many gods? There are many countries on planet earth. Similarly there could be many parts to heaven/hell, each controlled by the god/gods of various religions (there are more than 2000 religions the wrold over).
The gods and/or their accredited agents many be waiting at the entrance to the heaven/hell (some sort of no-man's land) to catch hold of the souls and push them into the heaven/hell as per their discretion.
