Hi
Yes by paying you have admitted to the debt and should continue paying.
Lowell are a genuine company but some of the debts that they purchase or chase for are often disputed debts. The debt may not be owed, once you have looked into the matter with the original creditor Vodafone.
What you should do.
1) Keep paying Lowell
2) Start a complaint with Vodafone. Send a letter by recorded delivery addressed to Customer Service Director, Complaints, Vodafone House, The Connection, Newbury, Berkshire RG14 2FN. You could make a subject access request under the Data Protection act asking them for full details of the account in question. It will cost you a fee of £10, which is the maximum they can charge. In the information, it should contain all the statements, all account information held and all letters they have sent to you. If they have sold the debt on, they should have written to the address held on their records.
What you may find, is that following your complaint to Vodafone, is that the debt is not actually due. If this is the case and Vodafone admit this in writing, you can request the money paid back, plus compensation.
If you read some of the other threads on this site, there have been cases where people have been chased for debts in error. I have a feeling that some of the mobile phone companies are not very good with their accounts records. Perhaps they show accounts are still running, when in fact they have been cancelled.
Huckster