PredictLeads API Credits Used Unexpectedly: Need Assistance

Hi everyone, I have a 50K row table and I was running my PredictLeads API.... to find the technology associated with each domain. After table finished running... it use all 100K Credits I had for the PredictLeads. It should suppose to use 50K only but it used double. Why is that? Anyone know the reason? The table used all my Predictleads credits. Any help or info would really appriciated.