Time slot of a deleted reocurring meeting

Hi! I need help.

I created a series of reoccurring meetings with meetings once a week and it included a registration form. 

One week needed to be off so I deleted one in between, but later the organizers changed the number of meetings so I had to allocate a meeting again in that week off. 

The thing is that I added a meeting into the series but doesn't allow me to put it in the right time frame since it says that it clashes with another meeting in the series, even though the past meeting doesn't exist anymore!

I can´t even recover the deleted meeting since it has been more than a week since I delete it. 

Is there any way to get the meeting in the right time slot? I can only allocate it a hour before or later

*PD: I can't make a new meeting since it has people registrated