She has been in a mutah marriage and the contract is for it to be above 50 years. The husband has left her and even moved out but refuses to get a proper Islamic divorce. She has tried everything she can to contact him directly and indirectly and he is completely ignoring everything. She was told to go to a marja’s office and they can end it for her, but she lives in the west and can’t get in touch with a marja’ in another country. What could the solution be according to sistani?

The period of 50 years exceeds the normal life of the people who are 31 years old, which makes the marriage void.
The other thing which makes it void is not mentioning a particular period, as according to the question, the period mentioned at the time of the contract was (above 50 years).
Hence, the said contract is void, and she can get married to anyone.