BT's ISDN services have been plagued by a series of crashes since a storm caused damage to its exchange equipment at the beginning of June.
Several companies in London and the south east have been frustrated by interruptions to their phone services, despite BT's assurance that an army of emergency engineers is working around the clock.
Robin Kent, European director at Wan communications vendor ADAX, complained: "Our lines went down for about three days after the storm. During the past two weeks, we have been cut off another three times."
He added: "BT's approach was better rehearsed each time it happened, suggesting the problem is very widespread. I still don't see how forces of nature could have caused this amount of trouble."
London based public relations company Catalyst was without email or telephone lines for four days at the end of last month.
A BT spokesman admitted: "We'd had a larger number of faults than usual, so it is taking longer to mop things up after the storm. We're working flat out, but there's a greater demand on our resources so we can't respond as quickly as we'd like. We hope to be back to normal response time as soon as possible."
However, Catalyst claims it was told by BT engineers that they were nowhere near back to normal. A Catalyst representative complained: "It caused severe disruption to our business and was made even worse by the fact that it was Networks Telecom week."
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