Window blind problem

To add to our electrical problems on our Rienza just for a change we had a problem with the window blind. Management decide to lower one of the fly screens followed by a loud bang and all the fly screen unrolled. 
The only way to roll the fly screen up was to remove the whole inner window frame , good fun on site in Germany  .
With the frame off I found the bit of plastic that holds the end of the blind in place under tension had snapped of allowing the blind to unroll under gravity. With a bit of bodge work and a self tapping screw I managed to roll up and secure the fly screen .
Can you get parts for these blinds. The lower screen is the concertina type with a sliver outer. 
The poor old Rienza threw up some challenges this holiday but we wont be beaten Just as feel better job I have modified the table storage in the wardrobe to stop it sliding about and tearing its mountings out of the bathroom wall. Next trip planned and booked, Flying Proms next.

Is it the Seitz blind, sounds like it. These might be what you need.

https://www.leisureshopdirect.com/caravan-accessories/caravan-blinds/seitz-blinds/spare-parts-for-dometic-seitz-blinds/tension-bushes-for-seitz-blinds-pack-of-2

Thanks Ploughlin, I will take the frame back off and have a proper look, it was a bodge and scarper job on site but that looks  a cheap repair.

When I took the frame off   bits of white plastic fell onto the seat. Until I get the window frame back off I wont know what I need. It is too hot to be fighting with frame screws at the moment. Once the weather has cooled I will let you know how I got on. I have used leisureshopdirect before but didnt think they would stock bits for a thirteen year old window blind.

Funnily enough I was just going to enquire about this as it happened to us on the last day of our hols.

Will have a look and see if it is the same bit that has broken linked to by Peter. Not sure that I will do the job myself as van under warranty and I don't want to make matters worse.

Let some one else do the job. I have removed two inner window frames on our Rienza to re-seal the windows. After getting the trim panels off the frame is a right pain, lots of screws in daft corners, not too be done in hot weather. I only did it on site to wind up the fly screen The fly screen is a good idea until you have to open the door then the midges come in by the squadron.

That's what I thought, Dave. If I can identify that is the problem I will get the part, it is cheap enough, as it will save 2 visits to the dealer as they won't have it.