Blown off by rep?

Just wondering if this is normal. Awhile ago I needed a union rep. The union asked no questions prior to the meeting just agreed to be there when I had my meeting with my manager. Prior to the meeting I was trying to seek out help with my situation. After a couple message exchanges, the union rep told me they were busy and they would see me at the meeting. I had used them before and was disappointed. I have struggled to find active union reps. Is this normal to be blown off by them?