Hello

What does your contrct with the letting agents say?
Normally you cant cancel your contract with them to pay commission during the duration of the tenancy of the tenants they have found.

I would have thought they would have still paid you less their commission.

Are the agents a member of NALS or other trade body?  It is strange that they are not returning you calls.

I would write and contact their trade body, write to the tenant to confirm if they have paid the rent and to who?
The trade body may be able to help.

keep us posted.
www.thelettingagents.co.uk