Do I go for a touch up ??

I need an advice cause I feel really lost.

So a few years ago I got a keratin hair treatment, I was trying it , it was amazing .

Then after yrs my hair grew longer , so I hated it . Cause in humid weather whatever I do it still frizzes up and become puffy and dry no matter what I apply .

Anyways last Monday I got another treatment , I paid a big amount , and I was happy cause after salon the results were amazing ,silky straight

But after the first wash, it is wavy now , not straight .

Anyways my mom went to the salon and showed them

They said come this week Friday and we will do a touch up and do again
Cause honestly

The results are gone in less than a week

But I have a question

They didnot tell me if they will charge me again,
What if after they did the treatment they recharged me again ?

Do I go to another salon

Or do I ignore it and try to accept the waves even though I paid to get it all straightened up with no waves cause it looks puffy and frizzy

Or do I go and not pay ??

Pls advice me

Am lost