How can I fix my BT Synergy 2110?

Basically 2 days ago it was loosing the base register every 5 minutes or so, and without any intervension at all it comes back to normal. When it happens to have the handset registered to the base, it rings however after a short while I answer the phone I will stop hearing the voice who's calling. Today I put it on charge. The red light on the base was switched on however the display on the handset was off. After 16 hours charging the screen was on (with the battery marking as empty and the antenna not flashing) when on the base, but went off as soon as I removed it. Moreover even when on the base the phone does not ring.

Anyone can give me a helping hand?