If you agree that you have to let them back as per Geneva, then the solution is obvious: let the 7million refugees back to the lands they were ethnically cleansed from in 1948 and onwards.
For cases where the original person is now dead (1948 was 75 years ago), i think its reasonable that that person's descendents should split appropriate compensation.
What im getting at here is - if someone was driven out and owned a 1 bedroom apartment, they are only owed a 1 bedroom apartment. If they had 50 grandchildren they are still owed only the single apartment not 50 apartments, one for each heir.
The other big issue is this was 75 years ago. Much of this property probably doesn't exist anymore. I think due to pure practicality, cash compensation would have to be the way to address this issue.