The solicitor who acted when you purchased the property has been negligent.
You only have six years from when this came to your notice to bring a claim against the solicitor so the clock is ticking.
You should not have to pay this money because this should have been dealt with when you bought the property.
I suggest that you get your current solicitor to write to the earlier solicitor asking them for details of their indemnity policy or getting their agreement to remove the charges within the next 7 days or agreed to pay your current solicitors costs for doing so.
You are under a duty to mitigate your loss, and hence, for the sake of £120, you might want to simply pay your current solicitor to remove the charges and then ask the old solicitor to pay that cost and if not, sue them in the Small Claims Court.
It is going to be cheaper to pay your current solicitors costs for losing the charges than it is to pay the extra £130 per month, every month, and your old mortgage which is dearer than your new mortgage.
Ultimately, the solicitor is liable for the cost of putting the title right you will not necessarily recover the extra mortgage cost unless your solicitor has been aware of it.
Can I clarify anything further for you?
Please rate the service positive. It doesn’t cost you anything but helps me greatly.
We can still exchange emails.