I did the same to ours but I think caught in the internal roof holding clips as I have one tiny hole above each clip, I'm so annoyed with myself, my excuse is that it was blowing a gale and we drove 5 hours to collect the van that day so probably not on the ball as usual! anyway I'm going to remove the duck tape patch and get some of that stuff recommended and do it properly

I'm glad I read this thread, as I now realise our Eriba is completely lacking an elastic cord. I have just ordered some, and will no doubt have fun trying to thread it with bits of bendy plastic or similar!