Strange dial tone.

[#1]

Yesterday, I put the phone down on a cold caller. Since then, the dial tone on my phone is an intermittent "beep" rather than the continuous tone. The phone still appears to be working ok and I can receive and make calls. I tried all the online advice to make sure everything is ok. A line test was run and it said there was an internal fault. I checked everything over again, and still get this intermittent tone. I don't want to call out an engineer which may end up costing a lot seeing as how the phone appears to be working in all other respects other than a strange dial tone. Any ideas?

[#2]

They've left you a voice message....1571

[#3]

Thanks for that strat. I don't particularly want to hear the message, but I'll call it to clear the line. Being a tight yorkshire git, will it cost anything?

[#4]

It shouldn't cost you anything to check the message.
If you'd prefer to just remove the call feature from the line moving forward you can do that Here