Rip it out and start again....doing it properly next time
Surely once you change a fitting in a bathroom it then needs rcd protection as you were the last one to touch that circuit and are then...
Cable needs changing so that there is an earth to protect the cable and must be rcd protected so you need a 3core and earth
Must be protected by an RCD and a Minor works cert issued
And dont forget your earth fly lead to back of switch
Get a sparks to look
What size in Kw are the heaters
Manufacturers instructions will state that the oven needs connecting by a qualified electrician
£60 call out and first half hour..then £45 per hour after that
£50.......Get in the real world
disconnect it now.....get rid of him..report him take more pics as proof then find a bit of rope for him
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