My BT line won't dial out in tone, only in pulse?

My BT line will not dial out using the tone settings on my phone only when pulse is selected. I have recently bought cordless phones that won't dial out but only receive incoming. Only when I plug in a relic of a phone that and switch to pulse settings can I call out.

When I have tone settings selected there is a dialling tone present but when the number is dialled, nothing happens only to receive a message to put the receiver down. Just to throw something else into the equation, I have broadband through a microfilter that will work. All microfilters are in working order.

Can anyone help??!!