managing agents not paying

Other

We have two properties in our locality and our agents - a three office firm also in our area- to whom we pay full management fees are very late in paying rents over to us. We have spoken to the tenants who feel they have paid up to date however we have not had the rent for one property since April.
We have repeatedly e-mailed the agents expressing our concerns and two weeks ago wrote to and e-mailed them giving notice that we will manage the properties our selves in future. We also wrote to the tenants to this effect.
We also asked for details of the deposit holders and the reference numbers relating to each deposit to be given to the tenants and to ourselves.
We have had no reply from the agents.
One tenant who spoke to the agents yesterday was told that they knew nothing of our taking on the management ourselves.
We are very worried and need the rents. Our tenants are also very concerned about their deposits. can you give any guidence about how to resolve this situation?