I believe you, but:
TAKE IT BACK, WITH RECEIPT , and they will remove it !!
Why would you be asking how to remove it, seeing how you ~just~ finished ruining one by the same foolish method? If you did not steal it, take it back where you bought it!!
It's mighty odd that:
1) The store did the same thing to you twice
2) That, after this happening to you the first time, you weren't on-guard and looking....just what exactly were you doing? Did you not remember what had just happened to you?
*If you take it back, w/receipt...the mgr. should put someone's balls in a sling !
It's SUPPOSED to ruin the shirt when you try to remove it yourself !!
That is the way the store "gets back" at people that shop lift. "If we cant have it (aka customer pays for the item) then no one will have it"
Since you're telling the truth, and did not steal the item, AND this is the second time it has happened to you....PLEASE take it back, and rub their face in it (but have the receipt in your hand)