Internet was not working.

[tufguy]

"This morning my internet was not working so I called the internet provider. He told me there is a problem and it would start in half an hour but it didn't start even after one hour so I called him again and got this problem fixed fast."

Please check.

 

[emsr2d2]

"This morning my internet was not working so I called the internet provider. [STRIKE]He[/STRIKE] The assistant told me there [STRIKE]is[/STRIKE] was a problem [STRIKE]and[/STRIKE] but that it would [STRIKE]start[/STRIKE] be back online in half an hour. [STRIKE]but[/STRIKE] Unfortunately, it [STRIKE]didn't start[/STRIKE] wasn't back up even after [STRIKE]one[/STRIKE] an hour so I called him again. [STRIKE]and[/STRIKE] [STRIKE]got[/STRIKE] This time, he fixed the problem [STRIKE]fixed[/STRIKE] fast."

Please check.

See above.

 

[tufguy]

See above.

"It wasn't back up even after one an hour so I called him again." Can we say "it didn't back up even after an hour?"

 

[emsr2d2]

No. You can say "it wasn't back up", to mean "it still wasn't working; it was still not working".
"It didn't back up" means "It failed to carry out a data backup" or "A data backup failed".

 

[tufguy]

No. You can say "it wasn't back up", to mean "it still wasn't working; it was still not working".
"It didn't back up" means "It failed to carry out a data backup" or "A data backup failed".

Can we say "yesterday my internet stopped working and didn't work for five hours. 'It started working in the evening' or 'it was back online in the evening at 6 PM'?"

 

[emsr2d2]

Can we say "Yesterday my internet stopped working and didn't work for five hours"?
Yes, if you capitalise and punctuate it correctly. It would be quicker and more natural to say "Yesterday, my internet was down for five hours."

Also, can we say 'It started working in the evening' or 'It was back online [STRIKE]in the evening[/STRIKE] at 6 PM'?
With my corrections above, both are correct.

See above.