How long does it take for an upper tibunal to make a decision on a case or allow the case to be heard again?

We are appealing against the first tiers decision to the upper tribunal.We requested to have a rehearing and we have not heard from the upper tribunal since febuary,almost four months to be precise.My layer advised that they could make a decision on their own or allow us to go back to court,however we are still waiting on what ever the decide.Anyone know how long it takes for a decision.thank you