Rising Damp : DPC or Bead?

Hi all,

I have an issue of rising damp from one wall of my house (circa 1930s) which has been pebble dashed. The wall has no beading.It has been pebble dashed so assume the DPC which was put there originally cannot be seen.

I have had two companies come over to take a look today and both offered different solutions.

One company has said I need to have DPC injected into the wall.
The other company said I dont need DPC but he would take the render off from ground to above the current DPC and add a bead above the original DPC. The wall currently has some hairline cracks which look as though they travel across around where the DPC currently is so they probably do not help.

Need some advice as to which is correct?!?! confused.

Is the wall a cavity wall or solid brick/block? If it is a cavity wall then it would make sense to find the DPC and knock off everything beneath it. Can you put a picture up of the damp wall so we can get a better idea of what it could be,

Most time the damp gets through is due to DPC being breached .Bell bead and french drain normally cures damp issues
I am not a firm believer in chemical injection

Moisture is penetrating the render and the render prevents it leaving, need hacking off and re-doing.
First company sound like cowboys.