If these people are making you pay �17 per month they are ripping you off. I assume they are a will writing company and that they prepared the wills for you. As they are executors at the moment they could well continue their ripping off when getting probate after death, so you are quite right to replace them as executors.
If their business approach is so customer unfriendly I would be a little concerned as to whether their work in preparing the wills has resulted in them properly expressing your wishes. Read them again very carefully. Unless you are totally certain that you fully understand them and that they do express your wishes you should get advice from someone who has the necessary knowledge. This probably means seeing a solicitor, but many solicitors do not charge much for simple wills. However, do not be talked into letting a solicitor (or a bank) be an executor - far better for your beneficiaries or trusted friends or relatives to do this.