Bulldog has blamed a "hiccup with its billing system" for a delay in collecting subscription fees.
Some punters of the broadband ISP had originally received an email informing them that their payment had been declined and failure to act could lead to an interruption of their service.
Shortly after, Bulldog issued an email saying that the previous email had been sent in error and that broadband accounts would "not be put on hold".
A third email sent last week explained: "For your information we are writing to let you know that there has been a delay in your April invoice being created. We do apologise for any inconvenience and hope to have an invoice to you for this period by mid May."
A spokeswoman for the Cable & Wireless-owned ISP said a new billing process had experienced teething issues resulting in a "hiccup with the billing system".
However, she explained that only a tiny number of customers - around 100 - were affected.
Separately, a disgruntled customer has set up a forum - Bulldog Hell - for Bulldog customers to "voice their opinion publicly" about the service. A spokeswoman for Bulldog told us: "If people have issues then they should contact us direct or use the official bulldog forum." ®