comma in the middle of construction: than... and than

Writing an essay on my trial region English test, I ran into a problem. I wanted to use doubled than, but I was not sure if it’s right to do such a thing, and if I should put a comma before the "and than". So, if it wouldn’t be a problem, could you please say which phrase (I’ll write them both below) is right and, also, explain why?

Computers have way more occasions to spend time conveniently than people who’re claiming this statement to be right are able to imagine, and than I’ve already mentioned earlier.

Computers have way more occasions to spend time conveniently than people who’re claiming this statement to be right are able to imagine and than I’ve already mentioned earlier.

I guessed I knew English punctuation a bit, at least a bit. Anyway, we should put a comma before "and" if it connects two sentences in a case when they both have a subject + verb (sorry for a poor phrase, I didn’t know how to say it in a proper way). This has seemed to be this case though I thought there’s a chance of not putting a comma there due to such a construction as "than… and than".

I appreciate any help.