Dog is deaf after ear infection treatment

My dog had a double ear infection and the vet treated her with an Oti-pack. It's apparently newer and a one time treatment that stays in the ears for 2 weeks. It's 3 different drugs mixed together. I was not familiar with it but they said they have had very positive feedback and you don't have to give them drops and clean them for 2 weeks. I let them do it and now my cockapoo is completely deaf. She is 12 years old and was losing some of her hearing but could definitely still hear. Has anyone had their dog treated with this? From what I've read, they said it could be temporary deafness or permanent. Please let me know if you have had this treatment done and if something similar has happened. Also wanted to warn people about it as it is nothing something the vet mentions before administering the treatment. Thank you!

Jenn