The way you stated the problem is ass-backwards and purposely worded to be confusing. There is no missing dollar.
Where is the money right now?
Your poor parents have $2. The fact that you borrowed from and paid them back separately is confusing and irrelevant, although it does suggest they are divorced (and it's probably your fault).
You have $98. There's $1 in your pocket plus the $97 value of your crappy, overpriced shirt. You could also say you have $1 and the store has $97. Either way, it accounts for the other $98.
2 + 98 = 100
Check it on a calculator if you need to.
Please don't become an accountant or a financial adviser if this is indicative of your general thinking process.