My F24 fiance M26 suffers from hearing-impairment. It's got severe in the past few months and he wears hearing-aid all the time.

My sister (19) and cousin (22) were visiting 2 nights ago for after going shopping. They were discussing my fiance's HA and arguing about whether the device would still function after being exposed to certain degree of heat or cold. They asked my fiance to do a little experiement but he refused to let them touch it.

While I was in the kitchen, my sister sneaked into the bedroom where my fiance was sleeping and took his HA. Then used the heat the hairdryer produced to test the device. I didn't know the device was ruined til late at night when my fiance told me his HA wasn't working properly. His hearing ability gradually declined and he started having headaches. I thought something was wrong with the device itself til my cousin contacted me on FB saying my sister took the device and used the hairdryer on it and lost the bet they both made. I was furious I went over to my parents house and confronted my sister. She was shocked and started crying after telling her she just ruined over 5000$ worth of medical device because of a stupid bet and that she needed to pay for it immediately. My wedding is in less than 2 weeks and my fiance can't even be aware of his surrounding without his HA so it won't happen til he get new HA and this stuff is expensive.

She freaked out after I demanded she pay 5000$ for a new HA because she didn't know it cost this much and complained the money she has saved is to pay for her tuition otherwise she won't be able to make any progress in college.

My parents begged me to postpone the wedding til they find a solution that all parties can agree on but postpoining the wedding is going to cost us a lot more than the price of hearing aid my sister is refusing to pay for. I had an argument with them because I was not only worried about the wedding but my fiance's health. It's been 2 days and he's been complaining from headache and feeling isolated. The Doctor warned against going long without HA and so this is concering.

My parents said they would've paid me themseleves if they had that kind of money but I was unreasonable to take away my sister's education money she worked for when I could postpone if I'm worried about not getting a new HA before the weeding... essentially making it about the wedding and accusing me of choosing a party that last few hours over my sister's future and education. I left their house and still stood my ground despite them telling me I'm being selfish for not working with them on a solution for this issue.

Further Info: Just to clarify the device was working up until late at night. then my fiance told me he was having issues hearing and the device stopped working all together hours later. I did not think my sister had anything do it until my cousin contacted me and my fiance while we were going to see his doctor to discuss the problem. Unfortunately My sister has done similar things in the past so It wasn't too surprising to find out she was behind it.

My parents tend to let my sister get away with either intentionally or unintentionally ruining others' belongings without any accountability. Last summer she ruined her friend's dad's car but wasn't told anything because my parents paid for the damages. Now because I'm family then it was clearly wrong of me to expect either her or my parents to pay.

I wanted to add this piece of Info, while my sister was the one who did. I'm pretty sure it was my cousin's idea. She is very rude to my fiancè and always thinks it's fine to make negative comments about him.