What counts as unfair creditor hassle?
For more details, see here
What can I do about it?
Come to us. We can write to your creditors, pointing out that they are in breach of the Financial Conduct Authority rules, and requiring them to contact you only in writing in future.
After that, you do need to open their letters and respond to them! If that thought troubles you, just bring all the letters to us - it will be huge relief, and your creditor will be much happier that someone is speaking to them.
If you'd like to write the letters yourself, you can find a template here