If this bump was someone else’s fault, ie the driver who was going the wrong way. You should only have to make your insurance company Direct Line aware. Surely it is up the other party’s insurance company to assist you. If they will not assist you then motability and Direct line can hire you a car and then claim from the other drivers insurance.
Typically your insurance deals with the claim and recovers costs from the third parties insurance provider. In some cases the third parties insurer will contact you first offering to carry out the work and provide a replacement vehicle, whils’t yours is being repaired. However, they are typically quite open who they are and will deal with the whole claim, not part of, as its cheaper for them to do this, providing you haven’t already filed a claim with your own insurer.