I would say no. The provider has already drawn down their funding so why would they charge an employer again?
You can specify that the employer pays for any re-sits if its on a standard but this would need to go into your contract.
Regarding the funding I had a similar issue. We took over 11 learners from a provider that went bust, they only had 2 months worth of funding left yet needed at least 6 months of work from us. The ESFA were very clear that we could not go over the maximum funding band and that if we needed extra to get them through the employer should pay out of their own pocket. They said the employer is responsible for making sure the provider is delivering on time etc.